The present invention relates generally to drink containers, and more particularly to self return lid assemblies for automatically sealing beverages within drink containers.
There are many types of drink containers in common use today. Users drink from these containers under a wide variety of circumstances in which the beverages are highly susceptible to being unintentionally spilled. These circumstances include, for example, operation of a vehicle, participation in sports, walking, etc. Due to the fluid nature of beverages, spills commonly occur through the open mouths of containers when the containers are jarred, tipped, dropped, or otherwise subjected to sudden movements.
Spills also frequently result from opening sealed drink containers, which have unexpected pressure build-up therein. For example, jarring a sealed container having a carbonated beverage therein typically causes the pressure to increase therein. Subsequently opening the container typically causes the beverage to unexpectedly gush out of the opening due to the pressure build up. Further, sealed containers having hot beverages contained therein may similarly release a small burst of hot steam upon opening the container. Since users obviously wish to prevent accidental spills, it is desirable to prevent the beverage from inadvertently escaping the container without adversely increasing the pressure therein.
One proposal for eliminating accidental spills associated with travel cups employs the use of a thin plastic lid that snaps onto the rim of a Styrofoam or paper cup. These lids are commonly found in fast food restaurants and coffee outlets. The lid typically has perforations to allow a user to form one or more holes allowing the user access to the beverage. By reducing the size of the opening through which the beverage exits the cup, the likelihood of spills is subsequently reduced.
However, these lids fail to eliminate accidental spills because the beverage may still escape through the opening despite its reduced size. For instance, jarring the cup can cause the beverage to splash out of the cup through its opening even though the cup may be in an upright position. This is particularly true when the cup is still relatively full. Moreover, the beverage can still pour out of the cup through the opening if the cup is tipped onto its side. If the cup is dropped, the lid can be dislodged from the cup and the entire contents of the cup can be lost.
Another proposal involves a cup and a lid that is secured to the cup by a threaded engagement. One variation of this proposal further requires a lid having a hole formed therein for the purpose of allowing a straw to pass through the lid. This configuration also includes a cap that is manually placed on the end of the straw to keep the beverage within the cup. Another proposal involves a pop-up vent on the lid which seals the cup when the vent is manually pushed down and permits beverage to exit the cup when the vent is pulled up.
In both proposals, the threaded engagement secures the lid to the cup to prevent the lid from being dislodged from the cup if it is dropped. Both proposals also effectively prevent a beverage from splashing out of the cup if it is jarred when oriented in a substantially upright position. However, unless the user manually places the cap onto the straw or pushes down the pop-up vent, the beverage can spill out of the cup if it is tipped onto its side.
Yet another proposal is a self-sealing closure on a drink container as disclosed in U.S. Pat. No. 5,186,353. Unfortunately, while the closure disclosed therein has improved sealability on its closure, it requires the container to have a handle in order for the user to unseal the closure, which may be undesirable. Further, it requires aligning the lever of the closure with the handle of the container for its proper use. This is disadvantageous in that if these containers are frequently reused, care must be taken to align the lever and handle each time they are reassembled.
Therefore, a need exists for an improved self-sealing closure that is operable independently of the container to which it is attached, and for a closure that when attached to a container eliminates spills while is in a sealed configuration. Also, there is a need for such a closure which eliminates the need to align the lever and handle each time the closure and container are reassembled.